proportion

noun

harmonious arrangement or relation of parts or elements within a whole, as in a design
“This chair has great proportions.”
balance
magnitude or extent
“a building of vast proportions”
dimension
the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree
“an inordinate proportion of the book is given over to quotations”
ratio
the quotient obtained when the magnitude of a part is divided by the magnitude of the whole
balance among the parts of something

symmetry

verb